System with sonic sensor for detection and monitoring of fluid processing characteristics

ABSTRACT

A system for detecting characteristics of a fluid includes a sonic sensor. The sonic sensor includes a transducer, a transduction surface, and an acoustically reflective pad member. The transducer may be contained within a probe body, and the transduction surface may be an element of the probe body. A stem may connect the pad member to the transduction surface. The transducer will generate pulses that are transmitted to the pad member via a fluid when the transduction surface and pad member are immersed in the fluid. The system will detect the pulses when reflected and use that data to determine a speed of sound within the fluid. The system may use the speed of sound to determine density, specific gravity and/or stiffness of the fluid. The system may use that determination to assess a level of processing activity of the fluid, such as fermentation activity.

RELATED APPLICATIONS AND CLAIM OF PRIORITY

This patent document claims priority to U.S. Provisional PatentApplication No. 62/818,926, filed Mar. 15, 2019, the disclosure of whichis fully incorporated into this document by reference.

BACKGROUND

The measurement of fluid characteristics in static and dynamicenvironments is important in many industrial processes. For example,when brewing beer or making another fermented beverage, it is desirableto monitor the processing activity to ensure that it is progressing atan expected rate. If fermentation is too quick or too slow, theresulting product may exhibit poor quality and may need to be discarded.

Characteristics such as the density, compressibility and acousticimpedance of a fluid may contain important information to indicate thestatus of fluid processing activity such as a beverage fermentationprocess. Of particular interest in many applications is thedetermination of fluid density. Typically, to make a density measurementof a fluid, an accurate volumetric measurement or removal of the fluidis required. However, for rapid or remote monitoring and particularly indynamic situations, a simplified approach is desired. Furthermore, asystem that can constantly measure these fluid characteristics withoutrequiring interruption or fluid removal is desired.

Obtaining a measurement of a density of a fluid has numerous advantagesfor various industrial applications, one of which is the alcoholicfermentation of beer. The alcoholic fermentation induced by the presenceof yeasts is a fundamental step in several biotechnological processes,including the production of beer. Obtaining density measurements of beeris beneficial as an indicator for determining whether the beer isproperly fermented. For industrial purposes, the exact prediction of thefluid density during the fermentation process as early as possible wouldbe of great value. This is especially useful during the fermentation ofbeer, considering the fact that the fermentation binds a huge amount ofmachine capacities and time. Possessing an appropriate process statuspredictor, preceding and subsequent steps could be coordinated better tomaximize resource utilization and minimize overall costs.

Simple ultrasonic techniques have been already proposed as a method todetermine the density of beer during the fermentation process.Ultrasonic methods provide a non-invasive and non-destructive system tomonitor the fermentation process. The non-invasive aspect of ultrasonicmethods is of particular importance for biotechnological or medicalpurposes, where hygienic or microbiological safety must be guaranteed.Ultrasonic devices have been developed which are capable of providingsome information concerning fluids. For example, devices usingultrasonic signals to determine the fluid level in containers aredisclosed in U.S. Pat. Nos. 3,357,246, 4,144,517 and 4,203,324. However,these devices have limited accuracy in certain processes such asfermentation and other biotechnological processes in which the fluidproperties are constantly changing and require additional measurementsto assist in the determination of fluid characteristics in real-time.

Accordingly, there exists a need for an easy-to-deploy, low-maintenance,high-sensitivity sensor device capable of autonomously, quickly andreliably measuring fluid characteristics in real-time. This documentdescribes a system that solves at least some of the problems describedabove.

SUMMARY

In various embodiments, a system for detecting one or morecharacteristics of a fluid includes a sonic sensor. The sonic sensorincludes a transducer, a transduction surface, and an acousticallyreflective pad member. The transducer may be contained within a probebody, and the transduction surface may be an element of the probe body.An optional stem may have one end that connects to the acousticallyreflective pad member and a second end that connects to the transductionsurface.

In at least some embodiments, the stem may include a metallic shellhaving an inner cavity that is filled with an epoxy. In at least someembodiments, the acoustically reflective pad member comprises a metallicpad surface having a face that is positioned to face the transductionsurface of the probe body and that is positioned to be parallel with thetransduction surface.

In at least some embodiments, the system may include a processor and amemory containing programming instructions that are configured to causethe processor to: (i) generate a signal that will cause the transducerto generate a set of pulses that will be transmitted to the pad membervia a fluid when the transduction surface and pad member are immersed inthe fluid, and (ii) receive, from the transducer, signals indicatingwhen reflected pulses have been received from the pad member. For atleast some of the pulses in the set of pulses, the processor maydetermine a time of generation, and a time at which a correspondingreflected pulse is received at the transduction surface. The processormay use the determined times and a length of the stem (if present), or adistance between the transduction surface and the acousticallyreflective pad member, to determine a speed of sound in a fluid that isin contact with the pad member, stem and transduction surface.

In some embodiments, the processor may use the speed of sound in thefluid to determine density, specific gravity or stiffness of the fluid.If the system uses the speed of sound in the fluid to determine aspecific gravity of the fluid, it may also use the specific gravity toassess fermentation activity of the fluid or API gravity of the fluid.

The system also may cause a display device to output a graphicrepresentation of the determined characteristics, such as density,specific gravity, API gravity, stiffness or fermentation activity. Invarious embodiments, the processor may include an onboard processor thatis positioned within the probe body and electronically connected to thetransducer and/or an offboard processor that is an element of acomputing device that is communicatively connected to the sonic sensor.

In various embodiments, a system for monitoring processing of a fluidincludes a sensor and a memory containing programming instructions thatare configured to cause a processor to use the one or morecharacteristics of the fluid to determine specific gravity of the fluidand a level of processing activity of the fluid. The processor willcause a display device to output a dynamic representation of thespecific gravity of the fluid, as determined by the processing devicebased on the one or more characteristics. The processor also will causea display device to output determined level of processing activity asdetermined by the processing device based on the one or morecharacteristics.

In some embodiments, the processing activity may include fermentation,as that of a beverage. If so, the dynamic representation of thedetermined level of processing activity may include a fermentation tankwith a dynamically changing cavity. Displayed characteristics of thecavity will change as the determined level of the fermentationincreases.

In some embodiments, the system may use the determined level offermentation to identify a remaining time for completion of fermentationof the fluid. If so, the processor may cause the display device tooutput a dynamic representation of the remaining time for completion ofthe fermentation of the fluid. In addition or alternatively, the dynamicrepresentation of the determined level of processing activity mayinclude a dynamically changing status bar. The status bar may include asegment representing a processing activity level and a segmentrepresenting a period during which the fluid may remain in a tank inwhich the sensor is present after processing is complete.

In some embodiments, the system may continue to determine the level ofprocessing activity of the fluid over a period of time. If so, it mayaccess a data set of previous processing activity for the fluid andidentify, from the data set, an expected level of processing activityover the period of time. The system may assess whether the determinedlevel of processing activity over the period of time deviates from theexpected level of processing activity over the period of time. When thedetermined level of processing activity over the period of time deviatesfrom the expected level of processing activity over the period of time,the system may cause the display device to generate an output indicatingsuch.

In some embodiments, the sensor may include a sonic sensor. The one ormore characteristics of the fluid comprise a speed of sound within thefluid. Using the one or more characteristics of the fluid to determinethe specific gravity of the fluid may include using the speed of soundand a bulk modulus of the fluid to determine the specific gravity of thefluid. Using the one or more characteristics of the fluid to determine alevel of processing activity of the fluid comprises identifying changesin the specific gravity of the fluid over a period of time and using thechanges to determine the level of processing activity. The system mayinclude a transducer, a processor, and programming instructions that areconfigured to cause the processor to: cause the transducer to generateand transmit signals toward a reflective surface; monitor signalsreflected from the reflective surface when received by the transducer;and use a time of generation of the generated signals and a time ofreceipt the received signals to measure the speed of sound in the fluid.

In various embodiments, to determine specific gravity of the fluid thesystem may use the speed of sound to determine a density of the fluid,and it may determine the specific gravity of the fluid as a ratio of thedensity of the fluid to a constant that is specific density of water.

In some embodiments, the sensor may include a sonic sensor, and the oneor more characteristics of the fluid comprise a speed of sound withinthe fluid. If so, to determine the specific gravity of the fluid thesystem may use the speed of sound of the fluid and a bulk modulus todetermine density of the fluid, and then determine the specific gravityof the fluid based on the density. The system also may use the specificgravity to determine API gravity of the fluid. If so, then the systemmay cause the display device to display the determined API gravity ofthe fluid.

In other embodiments, a system for monitoring processing of a fluid mayinclude a sonic sensor for measuring speed of sound in a fluid when thefluid in contact with the sensor. The system also may include a memorycontaining programming instructions that are configured to cause aprocessing device to use the speed of sound of the fluid and a bulkmodulus for the fluid to determine density of the fluid. The system mayuse the density to determine the specific gravity of the fluid. Thesystem may then use the determined specific gravity to determine a levelof processing activity of the fluid by identifying changes in thespecific gravity of the fluid over a period of time and using thechanges to determine the level of processing activity. The system maycause a display device to output a dynamic representation of thedetermined level of processing activity as determined by the processingdevice.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates elements of an example system for measuringcharacteristics of fluid that is being processed.

FIG. 2 is a cross-sectional view of elements of a sonic sensor that maybe used with the system of FIG. 1 .

FIG. 3 is a flowchart illustrating an example process of determiningfluid characteristics using a sonic sensor such as that of FIG. 2 .

FIGS. 4A-4C illustrate elements of a user interface for displayingprogress of beverage fermentation or other processing of a fluid.

FIG. 5 illustrates an example data set showing use of the system andmethods described below in a beer brewing process.

FIG. 6 illustrates how the data set may be used to graphically indicateprocessing activity that deviates from expected norms.

FIG. 7 illustrates example electronic components that may be used invarious aspects.

DETAILED DESCRIPTION

As used in this document, the singular forms “a,” “an,” and “the”include plural references unless the context clearly dictates otherwise.Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of ordinary skillin the art. As used in this document, the term “comprising” (or“comprises”) means “including (or includes), but not limited to.” Whenused in this document, the term “exemplary” is intended to mean “by wayof example” and is not intended to indicate that a particular exemplaryitem is preferred or required.

In this document, when terms such “first” and “second” are used tomodify a noun, such use is simply intended to distinguish one item fromanother, and is not intended to require a sequential order unlessspecifically stated. The term “approximately,” when used in connectionwith a numeric value, is intended to include values that are close to,but not exactly, the number. For example, in some embodiments, the term“approximately” may include values that are within +1-10 percent of thevalue.

When used in this document, terms such as “top” and “bottom,” “upper”and “lower”, or “front” and “rear,” are not intended to have absoluteorientations but are instead intended to describe relative positions ofvarious components with respect to each other. For example, a firstcomponent may be an “upper” component and a second component may be a“lower” component when a device of which the components are a part isoriented in a first direction. The relative orientations of thecomponents may be reversed, or the components may be on the same plane,if the orientation of the structure that contains the components ischanged. The claims are intended to include all orientations of a devicecontaining such components.

Additional terms that are relevant to this disclosure are defined at theend of this Detailed Description section.

FIG. 1 illustrates elements of an example system for measuringcharacteristics of a liquid or other fluid that is being processed. Thesystem is used with a fluid processing container 50, which in thisillustration is a fermentation tank such as that used in a beer, cideror other beverage fermentation process. Other fluid processingcontainers may be used for other fluid processing activities, such asbiological fluid processing systems, chemical manufacturing processes,milk production tanks, vats for producing food products such as soups,sauces or meat substitutes, flavoring and/or fragrance productionequipment, and natural gas or oil processing systems. The systemincludes a sonic sensor 10 that can be installed inside of the containerand which includes a fitting that connects to or is outside of thecontainer when the sensor is in place. The fitting may include or beelectrically connected to a transmitter that transmits signals to acommunication gateway 60, or the fitting may pass a wire that is used totransmit signals to the communication gateway 60. The gateway 60includes one or more ports 61 or receivers that receive signals from thesonic sensor 10 and: (i) relay the signals via a transmitter 62 to aremote server 72 via a communication network 73; and/or (ii) relay thesignals to a local computer 71 via the transmitter 62, either directlyor through the communication network 73. The gateway 60 is optional, asthe computer 71 may be directly connected to the sonic sensor 10, and ifthe sonic sensor 10 is equipped with a transmitter then the sonic sensor10 may transmit signals to the computer 71 and/or remote server 72either directly or via a communication network 73.

FIG. 2 illustrates a cut-away view of a sonic sensor 10 in accordancewith various embodiments. Sonic sensor 10 includes a probe body 12,which may include a housing having a first end that is connected to afitting 30. The probe body 12 housing may be cylindrical, or shaped inanother form such as a rectangular or conical shape, and formed of anyappropriate conductive material providing a hygienic or microbiologicalsafe surface such as American Iron and Steel Institute (AISI) Type 304or 316 stainless steel. The fitting 30 may be designed to provide aportal via which the probe may be inserted into a fluid processing tankand via which signals captured by the probe may be transmitted out ofthe tank, either via a wire or via a wireless transmitter. In variousembodiments, the fitting 30 may be of a universal sanitary fitting type,such as a Tri-Clamp type fitting having a 1 inch or 1.5 inch outsidediameter which may fit into standard openings of fermentation vessels, aDIN fitting for use with dairy production equipment, or another fittingthat is suitable for creating a sanitary seal with the container.However, it is to be understood that the fitting 30 is not limited toany particular shape, size or type, and it and may be any appropriatedesign that can be retrofit and/or provide a new installation into afluid container. In addition, if the fluid container is configured tohold the sonic sensor 10 so that its reflective pad member 14 floatsfreely within the fluid, or of a device is available to hold the sonicsensor 10 in such a position, a fitting 30 may not be required.

A second end of the probe body 12 includes transduction surface 26 forsignals received from an acoustically reflective pad member 14. Thetransduction surface 26 may be a closed end cap of the probe body 12, orit may be a member that is positioned proximate to and just inside oroutside of the end cap. The transduction surface 26 may be a flatcircle, rectangle, oval, square, or other shape. The reflective padmember 14 also may be a flat circle, rectangle, oval, square, or othershape, and it may or may not be the same shape as the transductionsurface 26. Optionally the reflective pad member 14 may a surface areathat is at least as large as that of the transduction surface 26 so thatacoustic signals transmitted from the transduction surface 26 willreflect off of the reflective pad member 14. The reflective pad member14 may be made of a metal such as stainless steel and is connected tothe probe body 12 through a stem 16, as the stem 16 includes a first endthat is connected to the reflective pad member 14 and a second end thatis connected to the transduction surface 26. When the reflective padmember 14, stem 16, and transduction surface 26 are immersed in thefluid, electric components in the probe body may generate an ultrasonicpulse that will enter the fluid from the transduction surface 26 andreflect back from the pad member 14. These signals can be used tomeasure the speed of sound through the fluid. The reflective pad member14 may include a substantially flat surface that is positionedsubstantially parallel to the transduction surface 26 and perpendicularto the longest dimension of the stem 16, and thus substantiallyperpendicular to the direction of propagation of the ultrasonic signal.

The stem 16 connects to the transduction surface 26, which iselectrically connected to a transducer 15, such as a piezoelectrictransducer, that will convert the ultrasonic signal to an electricalsignal. The stem 16 may be a heavily damped connector that includes ametallic housing (such as a stainless steel shell) that is filled with adamping material to reduce noise in the signal that it transfers fromthe reflective pad member 14 to the transduction surface 26. The dampingmaterial may be an epoxy, rubber, cork, or other material that providesdamping to the metallic housing. The stem 16 may thus serve as avibroacoustically absorptive connector.

Optionally, in some embodiments the vibroacoustically absorptive stem 16may be omitted if the reflective pad member 14 is positioned and securedwithin the fluid, held in place by a support structure. If so, thereflective pad member 14 will be positioned at a known distance from thetransduction surface 26, and also so that the surface of the reflectivepad member 14 is parallel to the transduction surface 26.

Optionally, the probe body 12, stem 16 and reflective pad member 14 maybe formed of a single piece of metal, machined to create a relativelynarrow bore inside of the stem 16 and a relatively larger bore inside ofthe probe body 12. This manufacturing process, if used, will not requireany welds or other connective structures to join the probe body 12, stem16 and reflective pad member 14.

The transduction surface 26 also may be electrically connected to atemperature sensor 17 so that the temperature sensor 17 can detect thetemperature of the transduction surface 26, which will be substantiallythe same as the temperature of the interconnected stem 16 and pad member14, and thus indicative of the temperature of the fluid which contactsthe stem 16 and pad member 14. The temperature sensor 17 and transducer15 may be positioned on one or more circuit boards 20 adhered to orproximate to the transduction surface 26.

The outputs of the temperature sensor 17 and transducer 15 areelectrically connected to an onboard processor 28. The processor 28 maybe a microprocessor that will execute programming instructions stored ona memory 29, or it may be an element of a microcontroller that includesa memory with programming instructions. The processor 28 will receivethe signals from the temperature sensor 17 and transducer 15 and usethose signals to determine various properties of the fluid, such asdensity, specific gravity or other characteristics.

When executing the programming instructions, the processor will causethe transducer 15 to generate a set of pulses that will travel from thetransduction surface 26 through the surrounding fluid to the reflectivepad member 14. The transducer 15 will be acoustically connected to thetransduction surface 26, either through direct connection or one or moreintermediate structures, so that sonic pulses output by the transducer15 will travel through the transduction surface 26. The stem 16 willhave a known length that the processor will use to measure the time istakes for each ultrasonic pulse to leave the transduction surface 26 andreturn after reflecting off the reflective pad 14. The system can usethis “time-of-flight” of the ultrasonic pulse to determine theultrasonic sound speed, which it may use as a proxy to determine one ormore characteristics of the fluid that is in contact with the reflectivepad 14.

By way of example, the density (ρ) of a fluid is related to theultrasonic sound speed (c) and the compressibility of the fluid asrepresented by a bulk modulus (β) according to the following equation:

$c = \sqrt{\frac{\beta}{\rho}}$

If the system receives as an input or stores a value of thecompressibility (β) of the fluid, the system may use this equation todetermine the fluid's density (ρ) at any point in time based on theultrasonic sound speed (c) at that time. In such applications, the sonicsensor 10 may be considered to be a sonic density sensor.

The processor may transfer the measured data via a communication port 22to an external processor (such as that of the computer 71 in FIG. 1 )for supplemental processing and data visualization. The communicationport 22 shown is a High-Definition Multimedia Interface (HDMI) port, butany connection for communicating measurements to an outboard analysisunit may be used.

In some alternative embodiments, instead of determining the fluidcharacteristics onboard the sonic sensor 10, the sonic sensor 10 maysimply transfer the data received from the temperature sensor 17 andtransducer 15 to an off-board computing device to perform the fluidcharacteristic determination outside of the sensor 10.

FIG. 3 illustrates an example method of determining fluidcharacteristics in a beverage fermentation process, such as may be usedin brewing beer, cider, wine, rice wine (such as sake), mead, kombucha,root beer, ginger beer. A system such as that described above will use asonic sensor such as that described in FIG. 2 to generate sonic pulses(at 301) and transmit the pulses to a reflective pad member that isplaced in the fluid. The sensor will then detect reflected pulses (at302) and determine the sound speed within the fluid (at 303). The speedof sound may simply be determined be a process such as (i) determiningthe time of travel of each pulse, as measured from the time ofgeneration to the time at which the transducer receives the reflectedpulse, and (ii) dividing the time of travel by the distance of travel(which is twice the length of the stem, which is also the distancebetween the reflective pad and the transduction surface). In practicethis equation may be modified by a factor that is a function of thefluid type, stem thickness, temperature or other variables.

At 306 the system may then use the determined speed of sound (c) todetermine a density (ρ) of the fluid. The system may do this using theequation described above, using a bulk modulus (β) in which:

$\rho = \frac{\beta}{c^{2}}$

The system will need to identify the bulk modulus (β) at 305 beforecompleting this calculation. The system may receive the bulk modulus asa user input via the user interface, or it may store the bulk modulus asa characteristic of the fluid in a data set. In general, the bulkmodulus (β) of a fluid is a thermodynamic property that may vary bytemperature, and thus the system also may need to identify thetemperature of the fluid (as detected by the temperature sensor) at 304before determining the particular bulk modulus for the temperature. Oncethe system receives the temperature (at 304) and an identification ofthe fluid, it may determine the bulk modulus (at 305) by a suitablecalculation, or by retrieving the bulk modulus from a data set stored inmemory.

At 307 the system may then use the density to determine one or moreother characteristics of the fluid. For example, the specific gravity ofa substance is a ratio of the density of the substance to the density ofa reference substance, such as water (which has a density of 1gram/cubic centimeter). The system may thus use the density to determinethe fluid's specific gravity. If the fluid is oil or a petroleumproduct, the system may determine specific gravity of the fluid and thenconvert that measurement to API gravity, where API=(141.5/SG)−131.5,where SG is the specific gravity.

At 308 the system may use the determined characteristics to assessand/or monitor the progress of the process and determine when theprocess is complete. For example, in fermentation and distillationprocesses, specific gravity can be used to monitor the process of thefermentation or distillation. When a target specific gravity isachieved, or when a rate of change of the specific gravity decreases andthe specific gravity remains relatively constant (i.e., below athreshold standard deviation) for a threshold period of time, theprocess may be considered to be complete. For example, when brewingbeer, the process may be considered to be complete when the specificgravity has dropped by 70 or 75% of its original level, or when thespecific gravity remains substantially constant for a period of threedays. Other levels and time frames may be used depending on the processand desired result.

This is illustrated in FIG. 5 , which shows results of an example casestudy with gravity measurements over time 501 of various batches of beerin a brewing facility. Each line in the graph representing a batch.During the first few days of fermentation 504, the fluid's specificgravity remains relatively high, until a day (at 505) during which thegravity experiences a significant drop. Gravity then then levels offafterward at 506 at a relatively stable lower value. The gravitymeasurements over time 501 correspond fairly well to the fermentationlevels over time 502. Gravity or density measurements alone may be usedas a proxy for fermentation level, or the system may calculate afermentation level using a function of gravity or density levels andother factors, such as elapsed time, temperature, or other factors.

Returning to FIG. 3 , at any point in the process, at 309 the system mayoutput any of the measured parameters (such as temperature or speed ofsound), calculated characteristics (such as density or specificgravity), or indication of progress of the process (such as fermentationactivity). The output may occur by an electronic message, via an audiooutput, or via a user interface. Examples of user interfaces will bediscussed below in the context of FIGS. 4A-4C.

The methods described above may be used in other fluid processingactivities in which measurements such as that of the fluid's specificgravity or density are useful to monitor progress of the process.Examples of such other processes include alcoholic beveragedistillation, hydrocarbon product processing (such as crude oil andpetroleum products, in which the system may determine API gravity),ingestible probiotic production and the manufacture of pharmaceuticals.In some such processes, the fluid's density may remain constant butother variables (such as stiffness) of the fluid may change. The systemmay look for changes in the values of those variables and use thosechanges (in view of the equations above) as indicia of a level ofprocessing activity (or at least a change in condition) of the fluid.

FIGS. 4A-4C illustrate an example user interface 400 for monitoringprocessing of a fluid, such as fermentation of a beverage which is shownin this example. The user interface presents information received fromthe sonic sensor and/or determined by a processor, and it also include adynamic representation of the determined level of fermentation (or otherprocess progress). In this case the dynamic representation includes avisual representation of a fermentation tank 401 with a dynamicallychanging cavity, as well as a status bar 410 that is in the form of acircle.

The user interface also includes a dynamically changing time field 402that indicates either (a) how much time has elapsed in the process, or(b) how much time is expected to remain in the process. If expected timeremaining is use, the system may determine this by subtracting elapsedtime from an expected time that is stored in a memory based on previousprocessing times for batches of the same or a similar product.Optionally, the system may dynamically adjust the expected time toremain if processing parameters indicate that at one or more points intime the fluid's gravity is more than a threshold level above or belowan expected value or range based on target data from previous batches asstored in memory.

The user interface also displays characteristics of the fluid such asoriginal specific gravity 403 or original extract as measured at areference time at or near the beginning of the process, the currentspecific gravity 404 as measured in real time, the temperature 406 ofthe fluid and other measurements or calculated parameters 407. In thisexample the other calculated parameter 407 is bubbles per minute, whichis a value that represents or is a function of the rate of fermentationactivity and the transformation of sugar to CO2 and alcohol generationand the resulting change of the gravity at any given point in time.

Before the process starts, FIG. 4A illustrates the tank 401 with anempty cavity, and the status bar 410 contains no shading. The originalspecific gravity 403 has not yet been determined, and no time 402 haselapsed.

FIG. 4B shows that after a time 402 of nearly 1.5 days, the originalgravity 403 has been identified, and the current gravity 404,temperature 406 and other parameters 407 (in this case bubbles perminute) are displayed. The dynamic representation's tank 401 shows thatcharacteristics of the cavity have changed to show beer in the tank withbubbles indicating that the fermentation process is active. The dynamicrepresentation's status bar 410 shows shading around a portion of thecircle, indicating that fermentation has started but is not yet even 25%complete.

FIG. 4C shows that after a time 402 of nearly 10 days, the originalgravity 403, current gravity 404, temperature 406 and other parameters407 (in this case bubbles per minute) continue to be displayed. Both thecurrent gravity 404 and the temperature 406 of the tank have dropped ascompared to that shown in FIG. 4B. Because the gravity has dropped andreached a substantially stable level, the dynamic representation's tank401 shows new characteristics—in this case bubbles no longerappear—indicating that the fermentation process has slowed or competed.The dynamic representation's status bar 410 shows shading aroundapproximately ¾ of circle, indicating that even though the fermentationprocess is complete the beer may remain in the tank for a period of timewhile the temperature is reduced to near freezing to clear the remainingyeast and other particulates, as depicted by the temperature 406 in FIG.4C.

In some embodiments, the user interface may include graphic outputs tohelp indicate whether a fermentation or other process is deviating fromexpected norms. For example, FIGS. 5A and 5B illustrate gravity 501 andcalculated fermentation activity 502 levels over time for severalbatches of a beer. Optionally, the system may include a user interfacefield that displays such results in graphic form such as that shown. Inthe examples of FIGS. 5A and 5B, the lines are fairly close together,which establishes a knowledge base that can be used to establish anormal range of gravity and fermentation level that would be expected atany particular point in elapsed time for the particular recipe.

Deviations from these expected norms can use the resulting product tohave a poor quality. For example, FIG. 6 illustrates of data fromseveral batches of beer in which batches collectively designated by 605(shown as dashed lines) are within expected norms, but batches 611 and612 (shown as solid lines) deviate from the expected norms by more thana threshold (such as a threshold standard deviation level). In batch611, gravity is not dropping as quickly as expected, and thusfermentation is occurring more slowly than expected. The brewer mayadjust for this by increasing the temperature, adding more yeast, ortaking other action to try to speed the fermentation process. Incontrast, in batch 612 the gravity is dropping and fermentation isoccurring more quickly than expected. The brewer may attempt to slowfermentation by adding malt, reducing the temperature, or taking otheraction to try to slow the fermentation process. In either case, if theprocess is deviating from expected norms, the system may illustrate itgraphically as shown, or it may simply display an alarm message alertingthe processor to take action.

FIG. 7 depicts an example of internal hardware that may be included inany of the electronic components of the system, such as the onboardhardware of the sonic sensor 10 of FIG. 2 , or that of the computingdevice 72 or server 72 of FIG. 1 . An electrical bus 700 serves as aninformation highway interconnecting the other illustrated components ofthe hardware. Processor 705 is a central processing device of thesystem, configured to perform calculations and logic operations requiredto execute programming instructions. As used in this document and in theclaims, the terms “processor” and “processing device” may refer to asingle processor or any number of processors in a set of processors thatcollectively perform a set of operations, such as a central processingunit (CPU), a graphics processing unit (GPU), a remote server, or acombination of these. Read only memory (ROM), random access memory(RAM), flash memory, hard drives and other devices capable of storingelectronic data constitute examples of memory devices 525. A memorydevice may include a single device or a collection of devices acrosswhich data and/or instructions are stored.

An optional display interface 730 may permit information from the bus700 to be displayed on a display device 735 in visual, graphic oralphanumeric format. An audio interface and audio output (such as aspeaker) also may be provided. Communication with external devices mayoccur using various communication devices 740 such as a wirelessantenna, an RFID tag and/or short-range or near-field communicationtransceiver, each of which may optionally communicatively connect withother components of the device via one or more communication system. Thecommunication device 740 may be configured to be communicativelyconnected to a communications network, such as the Internet, a localarea network or a cellular telephone data network.

The hardware may also include a user interface sensor 745 that allowsfor receipt of data from input devices 750 such as a keyboard, a mouse,a joystick, a touchscreen, a touch pad, a remote control, a pointingdevice and/or microphone. Digital image frames also may be received froma camera 720 that can capture video and/or still images. The system alsomay include a positional sensor 780 such as a global positioning system(GPS) sensor device that receives positional data from an external GPSnetwork. Various elements of the system (as installed in the sonicsensor) also may include a temperature sensor 780 and a transducer 790,as previously described in the context of FIG. 2 above.

In this document, the terms “electronic device,” “computer” and“computing device” refer to a device or system that includes a processorand memory. Each device may have its own processor and/or memory, or theprocessor and/or memory may be shared with other devices as in a virtualmachine or container arrangement. The memory will contain or receiveprogramming instructions that, when executed by the processor, cause theelectronic device to perform one or more operations according to theprogramming instructions. Examples of electronic devices includepersonal computers, servers, mainframes, virtual machines, containers,gaming systems, televisions, digital home assistants and mobileelectronic devices such as smartphones, fitness tracking devices,wearable virtual reality devices, Internet-connected wearables such assmart watches and smart eyewear, personal digital assistants, cameras,tablet computers, laptop computers, media players and the like.Electronic devices also may include appliances and other devices thatcan communicate in an Internet-of-things arrangement. In a client-serverarrangement, the client device and the server are electronic devices, inwhich the server contains instructions and/or data that the clientdevice accesses via one or more communications links in one or morecommunications networks. In a virtual machine arrangement, a server maybe an electronic device, and each virtual machine or container also maybe considered an electronic device. In the discussion above, a clientdevice, server device, virtual machine or container may be referred tosimply as a “device” for brevity. Additional elements that may beincluded in electronic devices are discussed above in the context ofFIG. 7 .

The terms “processor” and “processing device” refer to a hardwarecomponent of an electronic device that is configured to executeprogramming instructions. Except where specifically stated otherwise,the singular terms “processor” and “processing device” are intended toinclude both single-processing device embodiments and embodiments inwhich multiple processing devices together or collectively perform aprocess.

The terms “memory,” “memory device,” “data store,” “data storagefacility” and the like each refer to a non-transitory device on whichcomputer-readable data, programming instructions or both are stored.Except where specifically stated otherwise, the terms “memory,” “memorydevice,” “data store,” “data storage facility” and the like are intendedto include single device embodiments, embodiments in which multiplememory devices together or collectively store a set of data orinstructions, as well as individual sectors within such devices.

In this document, the terms “communication link” and “communicationpath” mean a wired or wireless path via which a first device sendscommunication signals to and/or receives communication signals from oneor more other devices. Devices are “communicatively connected” if thedevices are able to send and/or receive data via a communication link.

“Electronic communication” refers to the transmission of data via one ormore signals between two or more electronic devices, whether through awired or wireless network, and whether directly or indirectly via one ormore intermediary devices. Devices are “electronically connected” if apath for transmission of electronic signals exists between the twodevices.

In this document, the term “connected,” when referring to two physicalstructures and not used in the context of electronic or communicativeconnection, means that the two physical structures touch each other.Devices that are connected may be secured to each other, or they maysimply touch each other and not be secured.

In this document, the term “fluid” has its common meaning as anysubstance that has no fixed shape and yields easily to externalpressure. A fluid may be a liquid, a gas or a plasma. In addition, afluid may contain some solids so long as the overall substance will flowin response to the application of force.

The features and functions described above, as well as alternatives, maybe combined into many other different systems or applications. Variousalternatives, modifications, variations or improvements may be made bythose skilled in the art, each of which is also intended to beencompassed by the disclosed embodiments.

The invention claimed is:
 1. A system for detecting one or morecharacteristics of a fluid, the system comprising: a sonic sensorcomprising: a probe body comprising: a transduction surface, and atransducer that is acoustically connected to the transduction surface;an acoustically reflective pad member; and a stem having: a first endthat is connected to the acoustically reflective pad member, and asecond end that is connected to the transduction surface, wherein thestem comprises a metallic shell that contains a damping material.
 2. Thesystem of claim 1, wherein the damping material comprises an epoxy. 3.The system of claim 1, wherein the acoustically reflective pad membercomprises a metallic pad surface having a first face that is positionedto face the probe body, wherein the first face of the acousticallyreflective pad member is positioned to be parallel with the transductionsurface.
 4. The system of claim 1, further comprising: a processor; anda memory containing programming instructions that are configured tocause the processor to: generate a signal that will cause the transducerto generate a set of pulses that will be transmitted to the pad membervia a fluid when the transduction surface and pad member are immersed inthe fluid, and receive signals indicating when reflected pulses havebeen received from the pad member.
 5. The system of claim 4, furthercomprising additional programming instructions that are configured tocause the processor to: for at least some of the pulses in the set ofpulses, determine: a time of generation, and a time at which acorresponding reflected pulse is received at the transduction surface;and use the determined times and a length of the stem, or a distancebetween the transduction surface and the acoustically reflective padmember, to determine a speed of sound in a fluid that is in contact withthe pad member, stem and transduction surface.
 6. The system of claim 5,wherein the memory comprises additional programming instructions thatare configured to cause the processor to use the speed of sound in thefluid to determine density, specific gravity or stiffness of the fluid.7. The system of claim 6, wherein the memory comprises additionalprogramming instructions that are configured to cause the processor to:use the speed of sound in the fluid to determine a specific gravity ofthe fluid; and use the specific gravity to assess fermentation activityof the fluid.
 8. The system of claim 6, wherein the memory comprisesadditional programming instructions that are configured to cause theprocessor to use the speed of sound to determine API gravity of thefluid.
 9. The system of claim 4, wherein the processor comprises anonboard processor that is positioned within the probe body andelectronically connected to the transducer.
 10. The system of claim 5,further comprising a display device, and wherein the programminginstructions further comprise instructions to: cause the processor touse the determined speed of sound to determine one or morecharacteristics of the fluid; and cause the display device to output agraphic representation of the one or more characteristics.
 11. A systemfor detecting one or more characteristics of a fluid, the systemcomprising: a sonic sensor comprising: a probe body comprising: atransduction surface, and a transducer that is acoustically connected tothe transduction surface; an acoustically reflective pad member, and astem having: a first end that is connected to the acousticallyreflective pad member, and a second end that is connected to thetransduction surface, wherein the stem comprises a metallic shell thatcontains a damping material; a processor; and a memory containingprogramming instructions that are configured to cause the processor to:generate a signal that will cause the transducer to generate a set ofpulses that will be transmitted to the pad member via a fluid when thetransduction surface and pad member are immersed in the fluid, receive,from the transducer, signals indicating when reflected pulses have beenreceived from the pad member, for at least some of the pulses in the setof pulses, determine: a time of generation; and a time at which acorresponding reflected pulse is received at the transduction surface,and use the determined times and a distance between the transductionsurface and the acoustically reflective pad member, to determine a speedof sound in a fluid that is in contact with the pad member andtransduction surface.
 12. The system of claim 11, wherein theacoustically reflective pad member comprises a metallic pad surfacehaving a first face that is positioned to face the probe body, whereinthe first face of the acoustically reflective pad member is positionedto be parallel with the transduction surface.
 13. The system of claim11, wherein the memory comprises additional programming instructionsthat are configured to cause the processor to use the speed of sound inthe fluid to determine density, specific gravity or stiffness of thefluid.
 14. The system of claim 11, wherein the memory comprisesadditional programming instructions that are configured to cause theprocessor to: determine a specific gravity of the fluid; and use thespecific gravity to assess fermentation activity of the fluid.
 15. Thesystem of claim 11, wherein the memory comprises additional programminginstructions that are configured to cause the processor to use the speedof sound to determine API gravity of the fluid.
 16. The system of claim11, wherein the processor comprises an onboard processor that ispositioned within the probe body and electronically connected to thetransducer.
 17. The system of claim 11, further comprising a displaydevice, and wherein the programming instructions further compriseinstructions to: cause the processor to use the determined speed ofsound to determine one or more characteristics of the fluid; and causethe display device to output a graphic representation of the one or morecharacteristics.
 18. A method of detecting one or more characteristicsof a fluid, the method comprising: causing a sonic sensor that comprisesa transduction surface, a transducer, a stem, and an acousticallyreflective pad member to generate a set of pulses and transmit thepulses from the transduction surface to the acoustically reflective padmember through a fluid in which the transduction surface and theacoustically reflective pad member are immersed, wherein the stem isconnected to the acoustically reflective pad member and the transductionsurface and comprises a metallic shell that contains a damping material;detecting reflected pulses that are reflected from the acousticallyreflective pad member through the fluid to the transduction surface; forat least some of the generated pulses, determine: a time of generation,a time at which a corresponding reflected pulse is received at thetransduction surface, and use the determined times and a distancebetween the transduction surface and the acoustically reflective padmember, to determine a speed of sound in the fluid that is in contactwith the pad member and transduction surface; use the determined speedof sound to determine one or more characteristics of the fluid; andcause a display to output a graphic representation of the one or morecharacteristics.
 19. The method of claim 18, wherein the one or morecharacteristics comprise density, specific gravity or stiffness of thefluid.
 20. The method of claim 18, wherein: the one or morecharacteristics comprise a specific gravity of the fluid; and the methodfurther comprises: using the specific gravity to assess fermentationactivity of the fluid, and causing the display to output a graphicrepresentation of the fermentation activity.
 21. The method of claim 18wherein: the one or more characteristics comprise a specific gravity ofthe fluid; and the method further comprises: using the specific gravityto determine API gravity of the fluid, and causing the display to outputa graphic representation of the API gravity of the fluid.